It is known that a jet engine may be provided with a thrust reverser to reduce the stopping distance of the aircraft, and to increase safety when braking on a wet or icy runway.
Generally, a thrust reverser comprises at least two doors mounted pivotally about axes transverse to the jet of the engine and disposed downstream of the jet's exhaust nozzle. Each of the doors is operable between a stowed position and a deployed position in which it is arranged transversely with respect to the jet stream.
Commonly, the doors are controlled by means of at least one longitudinal jack. Locking devices, for example hooks, are positioned at an upstream side of the doors to lock them in a folded position.
In spite of the advantages offered during the braking of an aircraft, thrust reversers may present the disadvantage of impairing the engine's thrust. In order to partially remedy these disadvantages, French Patent FR-A-2 382 593 suggests forming the thrust reversers so that, in their stowed positions, the interior volume of the doors provides a sleeve which defines the final portion of the engine nozzle including the throat. Since this sleeve serves in part as the engine nozzle, the nozzle proper can be shorter than is usual; as a consequence, the total length of the engine provided with a thrust reverser can be reduced, thereby saving weight.
It is known in the prior art to construct an aircraft jet engine with thrust reverser doors which are pivotable about fore and aft pivotal connections, as in the Dickenson U.S. Pat. No. 4,194,692, filed Aug. 5, 1977, and Linderman U.S. Pat. No. 4,093,122 filed Nov. 3, 1976. In both these patents, however, the thrust reverser doors do not, in any of their controllable positions, define the minimum cross-sectional area of the engine's ejection nozzle. In both of these prior patents, the minimum cross-sectional area is defined by a separate, variably convergent nozzle, with the thrust reverser doors being configured to provide, in the flight regime, a divergent nozzle.